硒与甲状腺疾病课件.ppt

1、硒与甲状腺疾病2019-10硒的作用 1、抗氧化功能 2、保护心血管 3、抗辐射损伤能力 4、解毒及抗癌 5、其他功能（未知）硒在体内的存在形式 1、低分子量的硒化合物 2、硒蛋白的形式：GSH-Px PHG-Px 3、硒代半胱氨酸 SeC 硒蛋白第一个发现的硒蛋白：GSH-Px 谷胱甘肽过氧化物酶 硒是GSH-Px的必需成分 补硒可使GSH-Px活性增强 GSH-Px分布广泛，在肾脏中浓度最高 GSH-Px可抑制NF-B的活化硒蛋白第二个发现的硒蛋白：PHG-Px 磷脂过氧化谷胱甘肽过氧化物酶 硒是其的必需成分 活性部位与GSH-Px相同硒蛋白 还有一些硒蛋白 虽然全部功能未知，但它们的一些

2、功能已被人们了解，包括细胞内信号的氧化还原调节、氧化还原稳态和甲状腺激素代谢。在病理上，硒蛋白表达降低与硒蛋白N（SEPN）相关肌病与因甲状腺激素代谢缺陷（由SBP2遗传缺陷引起的脱碘酶缺乏）引起的先天性肌病直接相关。硒化合物硒代半胱氨酸 Sec Sec与硒蛋白结合，参与到UGA密码子的解码。硒的摄入 硒：Se 足量摄入：人每日摄取硒180-280g 有明显的防癌作用 过量：人每日摄取硒819g，敏感的人会出现硒中毒症状硒与疾病硒化合物和硒蛋白与很多疾病有关：大骨节病 克罗恩病（CD）甲状腺疾病，包括TAO 已与预防某些癌症、阿尔茨海默病、心血管疾病和寿命密切相关。硒与甲状腺疾病 1、Sele

3、nium status and over-expression of interleukin-15 in celiac disease and autoimmune thyroid diseases.2019 甲状腺对硒缺乏特别敏感，因为含硒蛋白质（含硒代半胱氨酸）在甲状腺激素的生物合成和活动中起着重要的作用 硒与甲状腺疾病 2、Selenium in Human Health and Disease.2019 selenium in the environment,dietary intakes,metabolism and status,functions in the body,thyr

4、oid hormone metabolism,antioxidant defense systems and oxidative metabolism,and the immune system.硒与甲状腺疾病3、Selenium and the Thyroid:A Close-Knit Connection.2019 Context:The recent recognition that the essential trace element selenium is incorporated as selenocysteine in all three deiodinases has dec

5、isively confirmed the clear-cut link between selenium and thyroid function.It has additionally been established that the thyroid contains more selenium than any other tissue and that selenium deficiency aggravates the manifestation of endemic myxedematous cretinism and autoimmune thyroid disease.硒与甲

6、状腺疾病3、Selenium and the Thyroid:A Close-Knit Connection.2019 Evidence Acquisition:Clinical reports as well as a large number of biochemical articles linking selenium to thyroid have been considered.Interventional,prospective,randomized,controlled studies,including large observational studies,suppleme

7、nting selenium in autoimmune thyroid disease,together with review articles published in Medline and Pubmed have undergone scrutiny.The methodological differences and variety of results emerging from these trials have been analyzed.硒与甲状腺疾病3、Selenium and the Thyroid:A Close-Knit Connection.2019 Eviden

8、ce Synthesis:Evidence in support of selenium supplementation in thyroid autoimmune disease is evaluated,the results herein presented demonstrating the potential effectiveness of selenium in reducing the antithyroid peroxidase titer and improving the echostructure in the ultrasound examination.Howeve

9、r,considerable discord remains as to who should comprise target groups for selenium treatment,who will most benefit from such treatment,the precise impact of the basal antithyroid peroxidase level,and the effect of disease duration on the treatment outcome.Clearly,further in-depth studies and evalua

10、tion are required concerning the mechanism of action of selenium as well as the choice of supplements or dietary intake.Conclusions:Maintenance of selenostasis via optimal intake not only aids preservation of general health but also contributes substantially to the prevention of thyroid disease.硒与甲状

11、腺疾病4、On the importance of selenium and iodine metabolism for thyroid hormone biosynthesis and human health.2019 The trace elements iodine and selenium(Se)are essential for thyroid gland functioning and thyroid hormone biosynthesis and metabolism.While iodine is needed as the eponymous constituent of

12、 the two major thyroid hormones triiodo-L-thyronine(T3),and tetraiodo-L-thyronine(T4),Se is essential for the biosynthesis and function of a small number of selenocysteine(Sec)-containing selenoproteins implicated in thyroid hormone metabolism and gland function.The Se-dependent iodothyronine deiodi

13、nases control thyroid hormone turnover,while both intracellular and secreted Se-dependent glutathione peroxidases are implicated in gland protection.Recently,a number of clinical supplementation trials have indicated positive effects of increasing the Se status of the participants in a variety of pa

14、thologies.These findings enforce the notion that many people might profit from improving their Se status,both as a means to reduce the individual health risk as well as to balance a Se deficiency which often develops during the course of illness.Even though the underlying mechanisms are still largel

15、y uncharacterised,the effects of Se appear to be exerted via multiple different mechanisms that impact most pronounced on the endocrine and the immune systems.硒与甲状腺相关性眼病（TAO）1、Graves ophthalmopathy,2019 2、Graves Orbitopathy，2019 在GO的中度至重度活动期疾病阶段，行抗炎治疗（主要是全身性类固醇的应用，眼眶照射），而且在威胁视力的严重阶段行眼眶减压手术。在轻度疾病中，对症

16、处理和硒补充就可以。在疾病的非活动阶段，手术（眼眶减压，眼外肌手术，眼睑手术）可以改善外观和功能。吸烟会增加GO的患病率和严重性，并降低治疗的效果。甲状腺功能恢复正常可以改善约60GO患者的症状。硒与甲状腺相关性眼病（TAO）3、Does selenium supplementation improve Graves ophthalmopathy?2019 有轻度Graves眼病（GO）的患者中，硒的补充可以起到改善软组织症状的作用。硒与甲状腺相关性眼病（TAO）4、Does selenium supplementation improve Graves ophthalmopathy?2019

17、 Background Oxygen free radicals and cytokines play a pathogenic role in Graves orbitopathy.Methods We carried out a randomized,double-blind,placebo-controlled trial to determine the effect of selenium(an antioxidant agent)or pentoxifylline(an antiinflammatory agent)in 159 patients with mild Graves

18、orbitopathy.The patients were given selenium(100 mu g twice daily),pentoxifylline(600 mg twice daily),or placebo(twice daily)orally for 6 months and were then followed for 6 months after treatment was withdrawn.Primary outcomes at 6 months were evaluated by means of an overall ophthalmic assessment,

19、conducted by an ophthalmologist who was unaware of the treatment assignments,and a Graves orbitopathy-specific quality-of-life questionnaire,completed by the patient.Secondary outcomes were evaluated with the use of a Clinical Activity Score and a diplopia score.硒与甲状腺相关性眼病（TAO）4、Does selenium supple

20、mentation improve Graves ophthalmopathy?2019 Results At the 6-month evaluation,treatment with selenium,but not with pentoxifylline,was associated with an improved quality of life(P0.001)and less eye involvement(P=0.01)and slowed the progression of Graves orbitopathy(P=0.01),as compared with placebo.

21、The Clinical Activity Score decreased in all groups,but the change was significantly greater in the selenium-treated patients.Exploratory evaluations at 12 months confirmed the results seen at 6 months.Two patients assigned to placebo and one assigned to pentoxifylline required immunosuppressive the

22、rapy for deterioration in their condition.No adverse events were evident with selenium,whereas pentoxifylline was associated with frequent gastrointestinal problems.硒与甲状腺相关性眼病（TAO）4、Does selenium supplementation improve Graves ophthalmopathy?2019 Conclusions Selenium administration significantly improved quality of life,reduced ocular involvement,and slowed progression of the disease in patients with mild Graves orbitopathy.讨论内容1、国内关于硒与甲状腺方面的研究还比较少2、能否做甲状腺和硒关系的相关研究？